> PS: I would love to see an immutable filesystem that does not allow writing to files, it only creates new files and garbage collects files that have no incoming reference anymore... Just like a garbage collected heap, and a bit like an OLAP databases (as far as I remember my DB theory...) Besides the performance bottleneck, does something like that exists?
Plan 9's venti is somewhat similar to this. though it's really a
storage backend that you implement a filesystem on top of, and the fs
winds up having a write cache, which is mutable in practice. The
interesting thing is that the block's location is the cryptographic
hash of its contents, which leads to all sorts of neat properties (as
well as requiring immutability).